This invention addresses the problem of how to obtain licensing permission to use material created by another, how to present assurances that permission was obtained for the use, and to track the entities entitled to a share of license fee payments.
All forms of human expression that can be recorded in a tangible medium are protected by copyright as “works of authorship”. The possible media of expression include text, two-dimensional static visual images, moving visual images, three-dimensional sculptures, music recorded with visual graphics, music recorded in digital pitch specifications, music recorded as soundwaves, and soundwave recordings of spoken words. This list is not exhaustive as new forms are continually being invented.
When a party who does not own the copyrights in a work of authorship wishes to make a use of that work of authorship, a license is generally required. The owners of the copyrights generally are willing to allow their works to be used in exchange for a fee. Copyright clearinghouses have been established for various kinds of works of authorship so that standing offers of licenses from the owners of copyrights can be assembled in one place from which they can easily be retrieved and accepted. Typically, the clearinghouses also process and enforce the payment of fees by those who accept the offered licenses and distribute the fees to those who are entitled to them. Using labor intensive methods, the clearinghouses generally track all of this information on paper and computer databases and handle communications with owners of copyrights, with their distribution agents, and with licensees in person, by telephone, by fax, and by e-mail.
The Internet has presented serious challenges to the established copyright clearance systems. Many forms of works of authorship are now published digitally on the Internet, including text, audiowave recordings, digital music specifications, still images, and videos. When these works of authorship are received by a client computer on the Internet, a copy can very easily be made on the client computer. The copy can then be reproduced, distributed, performed, displayed, or used to prepare a derivative work. Although it is very easy to make such uses of source works of authorship, it is very difficult to find the owners of copyrights in these works or their agents and obtain licenses. Furthermore, even if the source work of authorship is used with permission, it is difficult for a person viewing the reproduced work, including the owner of copyrights in the source, to verify that the source was, in fact, used with permission without exceeding the scope of the license.
Inventors have attempted to solve this problem by presenting technical means to prevent or discourage unauthorized use of works of authorship. These methods include using public key encryption to verify certificates of authority which are attached to works of authorship to prove that licenses have been obtained. They also include various methods of applying watermarks to a digital work of authorship to trace the reuse of a work.